Prevention, vigilance can outsmart Lyme disease

June 20, 2007|MICHELLE DEAL- ZIMMERMAN The Baltimore Sun

Lyme disease may be rare -- but it's out there. More than 30,000 people in the United States are infected each year. The positive message, however, says Dr. Robert Edelman, infectious-disease specialist and director of the Travelers' Health Clinic at the University of Maryland Medical Center, is that most infections can be avoided. "Even a tick that has been feeding for three days, your chance of getting Lyme disease is remote," he says. "Four out of five ticks are not infected." Q. Some ticks are difficult to see. When I'm checking my body, what areas should I pay closest attention to? A. There are three stages of ticks. The larval tick is when it first emerges from the egg and is small (about 1 millimeter). It's not the one that transmits Lyme disease. Larvae typically attach to field mice. When the ticks drop off, they've reached the next stage: nymphs. The nymphs cause 90 percent of the disease. They wait for the human or dog and crawl onto clothing until they can find a break between the clothing and skin. They can attach anywhere on the body, but favorite places are the back of the knee, thigh, groin, armpit, shoulder, abdomen and back. Q. Say I'm outside and notice a tick on my knee and pull it off right away. Do I still need to worry about Lyme disease? A. No. It's how quickly you can identify the tick and how quickly you get it off. If the tick appears to have been sucking your blood -- you can tell because the tick is swollen -- it's more of a concern. There's no Lyme disease you can catch from a tick attached for less than 24 hours to 36 hours. Q. You hear a lot about the bull's-eye rash, but other early symptoms of Lyme disease can be easy to overlook. How is it diagnosed? A. The rash is the only clinical symptom other than a blood test. The rash can last from seven days to four weeks. More than 90 percent of people (who contract Lyme disease) get a rash. At some point it becomes like a viral illness: You get headache, fatigue, muscle aches. A blood test, if it's positive, is helpful. But if it's negative, it's not helpful. It may take weeks after infection for a test to show positive. If you see a rash, don't wait a week to see if it goes away. Why? The longer you wait, it allows the bacteria to spread to other organs and invade the bloodstream. Q. What is the treatment? A. One of three different oral antibiotics -- doxycycline, amoxicillin, cefuroxime. The drugs will kill the bacteria in 97 percent of people infected. Take the right drug, with the right dose in the right period of time, and patients will be cured. Q. There's widespread debate about chronic Lyme disease. Are there some symptoms that linger after treatment? A. Yes, but we don't know if it's due to the Lyme disease or something else. Fewer than 10 percent of patients do not respond to treatment and have symptoms that may last for months -- headaches, sleep disorders, depression, memory issues. It's a mystery right now. Q. What's your best advice on prevention? A. Use DEET repellent on the skin when you go outside. Spray clothing with Permethrin. It will kill ticks and mosquitoes. It impregnates the fibers and will stay for several washings. It won't hurt humans. Tuck your shirt in. Remember, ticks look for a break between clothing and skin. Wear light-colored clothing. Don't wear dark clothes because you may not see the nymphal tick, which is a dark flesh color. Do a tick search. Check folds of skin closely. A tick that has attached will not transmit the disease for 24 to 36 hours. Control deer population. The adult ticks attach to deer where they feed and mate.